In wireless environments such as high-speed multimedia wireless communication services, there is a recent sudden increase of a demand for services needing high-speed data transmission. These services require the guarantee of Quality of Service (QoS) such as high data rate and low transmission delay time. In such high-speed data transmission systems, Inter Symbol Interference (ISI) caused by a multipath of a wireless channel greatly degrades the data rate. To solve this, there has been an active research for an Orthogonal Frequency Division Multiplexing (OFDM) technique of being resistant to frequency selective fading and being capable of canceling the ISI by splitting the whole bandwidth into several subcarriers and simultaneously transmitting data.
Alternatively, to provide multimedia services in the wireless environments requires a technique for correcting an error occurring in the wireless environments. For the sake of this, generally, a receiver makes use of Frame Error Correction (FEC) for error correction and Automatic Request and Response (ARQ) for retransmitting erroneous packets. A Hybrid Automatic Repeat reQuest (HARQ) technique, a combination of these two techniques, is used to obtain the advantages of the two techniques.
The HARQ technique is a technique for, when received packets include errors that cannot be decoded, improving a decoding success rate and enhancing performance by combining, without discarding, the erroneous packets with retransmission packets. The two HARQ types are: HARQ type I and HARQ type II/III. The HARQ type I called Chase Combining (CC) is a scheme in which, at a retransmission time, the same packet is retransmitted and combined. The HARQ type II/III is a scheme in which, at a first transmission time, no redundancy bits or only a very few are added to data packets. If packet transmission fails, redundancy bits increase through repeated transmission of the same packet and then, only the redundancy bits are retransmitted.
A combination of the OFDM technique and the HARQ technique provides great advantages of error correction in high-speed multimedia wireless communication and simultaneously, enables high-speed data transmission.
Presently, in an Institute of Electrical and Electronics Engineers (IEEE)802.16 communication system, when a Base Station (BS) transmits data to a Mobile Station (MS) using a HARQ processor, the MS should acquire information such as a Modulation and Coding Scheme (MCS) index including a modulation order and a Spectral Efficiency (SE) (or called a code rate), a resource size, a New Packet Indicator (NPI), a SubPacket IDentifier (SPID), and a HARQ Channel ID (ACID) so as to decode the data. Thus, the BS transmits the above information to the MS through a HARQ MAP control message.
However, there is a problem that, because the BS always has to map a value of the information to an allocated MAP region and transmit the mapped value whenever there is data to be transmitted to the MS, a MAP overhead is generated.